1. Field of the Invention
The present invention relates to a semiconductor integrated circuit adapted to carry out an operation test. In particular, it relates to a semiconductor integrated circuit having a multiplexed functional selection circuit which enables the integrated circuit to be set to a conventional operation mode as well as other operation modes, for example, a test operation mode.
2. Description of the Related Arts
In general, the operational efficiency of semiconductor integrated circuits is checked after manufacture, to ensure that the circuits will function properly in normal use, for example, when subjected to conditions of normal use, for example, when subjected to conditions of normal user operation. This check is carried out by a test operation, and is applied generally to simple logic circuits.
A memory usually contains a combination of many input patterns, and therefore, a long time is needed for carrying out a test of the circuits therein. in some cases, however, whether an internal circuit is operating normally cannot be determined clearly by a conventional input pattern, and a problem arises in that a satisfactory test of the circuit cannot be carried out.